<!DOCTYPE html>	
<html lang="en">
   <head>
      <meta charset="utf-8">
      <title>w0929_4_event</title>
      <script>
      	windows.onload=function(){};
      	//1.id가 byn01버튼클릭하면 user가 입력한  id값을 경고창에 출력
      	
      	//user가 입력한 id값이 비어잇으면 id는 필수입력입니다 출력.
      </script>
   </head>
   <body>
		<form name="frm1" id="frm1" action="" method="get">
			<label for="userName">id : </label>
			<input type="text" name="userName" id="userName" />

			<input type="button" value="id값 확인" id="btn01" />
			<input type="submit" value="확인"/>
		</form>
   </body>
</html>